Forming evacuation channels during single and multi-layer extrusion process
A method for making a vacuum packaging film includes flowing a plastic melt, from a multi-layer extruder, onto a rotating roller. The plastic melt is then cooled while simultaneously imparting a pattern, via a pattern imparting means, onto the plastic melt resulting in the vacuum packaging film.
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This application claims the benefit of Henry Wu's co-pending U.S. Provisional Patent Application No. 60/457,496, filed on Mar. 24, 2003, which is incorporated herein by reference.
FIELD OF THE INVENTIONThe present invention relates generally to manufacturing of vacuum packaging film, and more particularly to manufacturing patterned vacuum packaging film.
BACKGROUND OF THE INVENTIONVacuum packaging film is used for vacuum sealing of perishable items. Due to the film's versatility in producing vacuum-sealed packages of various sizes, its popularity has increased in recent years. As a result, continuous product improvement is required on the part of manufacturers in order to stay competitive. However, current methods for producing vacuum packaging film economically fail to meet the requirements of today's demanding marketplace.
Some of these requirements include the ability to produce a multi-layered product embedded with a pattern. Those skilled in the art will readily recognize that the combination of multi-layers and a pattern help to produce a vacuum packaging film that is gas-impermeable, in relation to the contents inside a package, as well as free of trapped air-zones. The presence of the pattern helps to prevent trapped-air-zones when contents are sealed therein.
The process described in
While manufacturing line 200 is capable of producing a two-layered patterned film. In order to produce additional layers, further manufacturing steps must be taken. Additionally, flowing a patterned layer onto an already formed layer may still result in structural flaws within the patterned film 220. The process of
Accordingly, what is needed is a method and apparatus to manufacture vacuum packaging film having multiple layers of substantially improved structure in an easy to manufacture and therefore economical process.
SUMMARY OF THE INVENTIONThe present invention fills these needs by providing a multi-layer extruder that is capable of producing a plastic melt that congeals into multiple layers. In combination with a pattern-producing tool, a pattern can then be imprinted as the melt passes over it. As a result, a multi-layer patterned vacuum packaging film can be produced.
A method for making a vacuum packaging film, in accordance with an embodiment of the present invention, includes flowing a plastic melt, from a multi-layer extruder, onto a rotating roller. The plastic melt is then cooled while simultaneously imparting a pattern, via a pattern imparting means, onto the plastic melt resulting in the vacuum packaging film.
A method for making a vacuum packaging film, in accordance with another embodiment of the present invention, includes flowing a plastic melt, from a multi-layer extruder, onto a rotating cooling roller. The plastic melt is then cooled, on the rotating cooling roller, into the vacuum packaging film.
A method for making vacuum packaging film, in accordance with yet another aspect of the present invention, includes flowing a plastic melt, from a multi-layer extruder, onto a cooling plank. The plastic melt is then cooled, as it flows over the cooling plank, into a vacuum packaging film.
A method for making vacuum packaging film, in accordance with yet another embodiment of the present invention, includes flowing a plastic melt, from a multi-layer extruder, in the vicinity of an air-knife. The plastic melt is then cooled, as it flows in the vicinity of the air-knife, into a vacuum packaging film.
An apparatus for producing a vacuum packaging film, in accordance with a final embodiment of the present invention, includes a multi-layer extruder for producing a plastic melt. Also included is a pattern imparting means for imprinting a pattern onto the plastic melt as it congeals into the vacuum packaging film.
An advantage of the present invention is that a multi-layer, patterned vacuum packaging film can be produced economically and yet still meet necessary demanding technical requirements. Additionally, the use of an air-knife, or conversely the inverse vacuum, enables custom patterns to be easily implemented as opposed to changing a roller embedded with an inverse pattern.
These and other advantages of the present invention will become apparent to those skilled in the art after reading the following descriptions and studying the various figures of the drawings.
As will be appreciated, the apparatus 300 may include a variety of other mechanisms useful in facilitating manufacture. For example, the apparatus 300 may include a temperature control device for controlling the cooling temperature of the cooling roller 208. The apparatus 300 may include motor controls for adjusting and controlling rotation speed of the cooling roller 208.
The apparatus 300 may include a laminating roll that through mechanical pressure applies the melt 304 onto the pattern of the cooling roller 208. Generally a cooling roll diameter is larger than a laminating roll diameter, 150% to 300% is suitable, but this may be implemented as desired.
The pattern may take on a variety of shapes including an uneven pattern, a random pattern, a wave pattern, a striped pattern, or a zigzag pattern. This pattern may be formed in any manner on the cooling roller 208, including on the entirety of the cooling roller 208, or may be disposed in stripes or randomly. The zigzap pattern in particular is described in more detail below with reference to
Turning next to
With reference to
The zigzag pattern 802 provides a variety of benefits. In particular, the varying size of channels formed by the zigzag pattern 802 retards fluid flow during vacuum evacuation of a vacuum packaging bag formed from the vacuum packaging film 800.
In view of the foregoing, it will be appreciated by one skilled in the art that a pattern imprinting means can include the cooling roller with the inverse pattern, a cooling plank with an inverse pattern, an air-knife, an inverse-vacuum and the like.
An advantage of the present invention is that a multi-layer, patterned vacuum packaging film can be produced economically and yet still meet necessary demanding technical requirements. Additionally, the use of an air-knife, or conversely the inverse vacuum, enables custom patterns to be easily implemented as opposed to changing a roller embedded with an inverse pattern.
While this invention has been described in terms of certain preferred embodiments, it will be appreciated by those skilled in the art that certain modifications, permutations and equivalents thereof are within the inventive scope of the present invention. It is therefore intended that the following appended claims include all such modifications, permutations and equivalents as fall within the true spirit and scope of the present invention.
Claims
1. A method for manufacturing a multi-layer film for use in vacuum packaging applications, said method comprising the steps of:
- heat-extruding a first material onto a spinning cooling roll;
- heat-extruding a second material onto said spinning cooling roll such that said first and second extruded materials bond in intimate and comprehensive contact forming first and second layers of said multi-layer film during a cooling of said first and second extruded materials; and
- said cooling roll simultaneously applying a pattern to and cooling said first and second layers, said pattern forming channels suitable for evacuation of gas from a vacuum packaging bag made of said multi-layer film.
2. A method for manufacturing a multi-layer film as recited in claim 1, wherein said first material is a heat-sealable resin.
3. A method for manufacturing a multi-layer film as tecited in claim 2, wherein said second material is a gas impermeable material.
4. A method for manufacturing a multi-layer film as recited in claim 3, further including an act of heat-extruding a first bonding material in between said first and second material, said first bonding material forming a first bonding layer between said first and second layers.
5. A method for manufacturing a multi-layer film as recited in claim 4, further comprising the act of heat-extruding a second bonding material and a structural material to form a second bonding layer and a structural layer, said second bonding layer bonding said structural layer to said second layer, said structural layer intended to provide additional strength to said multi-layer film.
6. A method for manufacturing a multi-layer film as recited in claim 5, wherein said act of applying a pattern operates to apply said pattern to all five layers of said multi-layer film.
7. A method for manufacturing a multi-layer film as recited in claim 1, wherein the act of applying a pattern to said first and second layers is accomplished by providing said pattern on the circumferential surface of said cooling roll.
8. A method for inanufactuzing a multi-layer film as recited in claim 7, further including the act of positioning a laminating roll to apply pressure to the extruded materials in order to apply said pattern formed on the circumferential surface of said cooling roll onto said multi-layer film.
9. A method for manufacturing a multi-layer film as recited in claim 8 further including the act of controlling a temperature of said cooling roll in order to properly effectuate cooling and fonnation of said first and second layers.
10. A method for manufacturing a multi-layer film as recited in claim 1, wherein said pattern is a zigzag pattern.
11. A method for manufacturing a multi-layer film as recited in claim 1, wherein said channels formed by said pattern have a varying width thereby retarding fluid flow therethrough.
12. The method as recited in claim 7 wherein said cooling roller contains an inverse-pattern that imparts a pattern onto said vacuum packaging film.
13. A method for manufacturing a multi-layer film for use in vacuum packaging applications, said method comprising the steps of:
- heat-extruding a first material onto a patterned cooling plank;
- heat-extruding a second material onto said patterned cooling plank such that said first and second extruded materials bond in intimate and comprehensive contact forming first and second layers of said multi-layer film during a cooling of said first and second extruded materials;
- said cooling plank simultaneously applying a pattern to and cooling said first and second layers, said pattern forming channels suitable for evacuation of gas from a vacuum packaging bag made of said multi-layer film; and
- directing said patterned multi-layer film over said a cooling roll.
14. A method for manufacturing a multi-layer film as recited in claim 13, further including the act of controlling a temperature of said cooling plank to properly effectuate cooling and fonnation of said first and second layers.
15. The method as recited in claim 13 wherein said cooling plank contains an inverse-pattern that imparts a pattern onto said vacuum packaging film.
16. A method for manufacturing a vacuum packaging bag, said method comprising:
- a) forming a first patterned film sheet including: i) heat-extruding a first material onto a spinning cooling roll; ii) heat-extruding a second material onto said spinning cooling roll such that said first and second materials bond in intimate and comprehensive contact forming first and second layers of said first patterned film sheet during a cooling of said first and second extruded materials; and iii) said coaling roll simultaneously applying a pattern to and cooling said first and second layers, said pattern forming channels suitable for evacuation of gas from said vacuum packaging bag made in part of said first and second patterned film sheet;
- b) bonding a second film sheet onto said first film sheet via sealing opposing sides to form a pouch with two open ends;
- c) sizing said pouch to a desired size; and
- d) bonding a one of said open ends to form a vacuum packaging bag.
17. A method of manufacturing a vacuum packaging bag as recited in claim 16, wherein said pattern is a zigzag pattern.
18. A method of manufacturing a vacuum packaging bag as recited in claim 16, wherein smd second film sheet is patterned.
19. A method of manufacturing a vacuum packaging bag as recited in claim 16, wherein bonding said second film sheet onto said first film sheet includes applying heat along said opposing sides.
20. A method of manufacturing a vacuum packaging bag as recited in claim 16, wherein bonding said second film sheet onto said first film sheet includes applying pressure along said opposing sides.
21. A method for manufacturing a roll of vacuum packaging bag material, said material comprising:
- a) forming a first patterned film sheet including: i) heat-extruding a first material onto a spinning cooling roll; ii) heat-extruding a second material onto said spinning cooling roll such that said first and second materials bond in intimate and comprehensive contact forming first and second layers of said first patterned film during a cooling of said first and second extruded materials; and iii) said cooling roll simultaneously applying a pattern to and cooling said first and second layers, said pattern operable to form channels suitable for evacuation of gas from said vacuum packaging bag made of said first and a second patterned film sheet;
- b) bonding said second film sheet onto said first film sheet via sealing opposing sides to form a pouch with two open ends; and
- c) forming said pouch into said roll of vacuum packaging material.
22. A method for manufacturing a roll as recited in claim 21, wherein said pattern is a zigzag pattern.
23. A method for making vacuum packaging film comprising:
- heat-extruding a first material in the vicinity of an air-knife;
- heat-extruding a second material such that said first and second extruded materials bond in intimate and comprehensive contact forming first and second layers of said multi-layer film during a cooling of said first and second extruded materials in the vicinity of said air-knife; and
- applying a pattern to said first and second layers while simultaneously cooling said first and second extruded materials, said pattern operable to form channels suitable for evacuation of gas from a vacuum packaging bag made of said multi-layer film.
24. A method as recited in claim 23 wherein said air-knife in an inverse-vacuum.
25. A method as recited in claim 23 wherein said air-knife imparts said pattern onto said vacuum packaging film.
26. A method recited as in claim 24 wherein said air-knife imparts said pattern onto said vacuum packaging film.
274447 | March 1883 | Kennish |
1938593 | December 1933 | Jarrier |
2085766 | July 1937 | Potdevin et al. |
2105376 | January 1938 | Scott |
2265075 | December 1941 | Knuetter |
2387812 | October 1945 | Sonneborn et al. |
2429482 | October 1947 | Munters |
2480316 | August 1949 | Blair et al. |
2607712 | August 1952 | Sturken |
2609314 | September 1952 | Engel et al. |
2633442 | March 1953 | Caldwell |
2642372 | June 1953 | Chittick |
2670501 | March 1954 | Michiels |
2690206 | September 1954 | Mueller |
2695741 | November 1954 | Haley |
2759866 | August 1956 | Seymour |
2772712 | December 1956 | Post |
2776452 | January 1957 | Chavannes |
2778171 | January 1957 | Taunton |
2778173 | January 1957 | Taunton |
2789609 | April 1957 | Post |
2821338 | January 1958 | Metzger |
2856323 | October 1958 | Gordon |
2858247 | October 1958 | De Swart |
2913030 | November 1959 | Fisher |
2916411 | December 1959 | Villoresi |
2960144 | November 1960 | Graf |
3026231 | March 1962 | Chavannes |
3060985 | October 1962 | Vance et al. |
3077262 | February 1963 | Gaste |
3077428 | February 1963 | Heuser et al. |
3098563 | July 1963 | Skees |
3102676 | September 1963 | Danelli et al. |
3113715 | December 1963 | Pangrac |
3135411 | June 1964 | Osborne |
3141221 | July 1964 | Faulls, Jr. |
3142599 | July 1964 | Chavannes |
3149772 | September 1964 | Olsson |
3160323 | December 1964 | Weisberg |
3224574 | December 1965 | McConnell et al. |
3237844 | March 1966 | Hughes |
3251463 | May 1966 | Bodet |
3325084 | June 1967 | Ausnit |
3334805 | August 1967 | Halbach |
3381887 | May 1968 | Lowry |
3411698 | November 1968 | Reynolds |
3423231 | January 1969 | Lutzmann |
3516217 | June 1970 | Gildersleeve |
3533548 | October 1970 | Taterka |
3565147 | February 1971 | Ausnit |
3575781 | April 1971 | Pezely |
3595467 | July 1971 | Goglio |
3595722 | July 1971 | Dawbarn |
3595740 | July 1971 | Gerow |
3600267 | August 1971 | McFedries, Jr. |
3661677 | May 1972 | Wang |
3785111 | January 1974 | Pike |
3799427 | March 1974 | Goglio |
3809217 | May 1974 | Harrison |
3833166 | September 1974 | Murray |
3895153 | July 1975 | Johnston et al. |
3904465 | September 1975 | Haase et al. |
3908070 | September 1975 | Marzolf |
3937395 | February 10, 1976 | Lawes |
3958391 | May 25, 1976 | Kujubu |
3958693 | May 25, 1976 | Greene |
3980226 | September 14, 1976 | Franz |
3998499 | December 21, 1976 | Chiarotto |
4018253 | April 19, 1977 | Kaufman |
4066167 | January 3, 1978 | Hanna et al. |
4098404 | July 4, 1978 | Markert |
4104404 | August 1, 1978 | Bieler et al. |
4105491 | August 8, 1978 | Haase et al. |
4155453 | May 22, 1979 | Ono |
4164111 | August 14, 1979 | Di Bernardo |
4179862 | December 25, 1979 | Landolt |
4186786 | February 5, 1980 | Kirkpatrick |
4212337 | July 15, 1980 | Kamp |
4215725 | August 5, 1980 | Callet et al. |
4295566 | October 20, 1981 | Vincek |
4310118 | January 12, 1982 | Kisida et al. |
4340558 | July 20, 1982 | Hendrickson |
4370187 | January 25, 1983 | Katagiri et al. |
4372921 | February 8, 1983 | Sanderson et al. |
4449243 | May 15, 1984 | Platel |
4486923 | December 11, 1984 | Briggs |
4532652 | July 1985 | Herrington |
4551379 | November 5, 1985 | Kerr |
4569712 | February 11, 1986 | Shibano et al. |
4575990 | March 18, 1986 | Von Bismarck |
4576283 | March 18, 1986 | Fafournoux |
4576285 | March 18, 1986 | Goglio |
4579756 | April 1, 1986 | Edgel |
4583347 | April 22, 1986 | Nielsen |
4626574 | December 2, 1986 | Cancio et al. |
4658434 | April 14, 1987 | Murray |
4669124 | May 1987 | Kimura |
4672684 | June 9, 1987 | Barnes et al. |
4683702 | August 4, 1987 | Vis |
4705174 | November 10, 1987 | Goglio |
4712574 | December 15, 1987 | Perrott |
4747702 | May 31, 1988 | Scheibner |
4756422 | July 12, 1988 | Kristen |
4756629 | July 12, 1988 | Tilman et al. |
4778282 | October 18, 1988 | Borchardt et al. |
4786285 | November 22, 1988 | Jambor |
4812056 | March 14, 1989 | Zieke |
4834554 | May 30, 1989 | Stetler, Jr. et al. |
4841603 | June 27, 1989 | Ragni |
4871264 | October 3, 1989 | Robbins, III et al. |
4877334 | October 31, 1989 | Cope |
4887912 | December 19, 1989 | Stumpf |
4890637 | January 2, 1990 | Lamparter |
4892414 | January 9, 1990 | Ausnit |
4903718 | February 27, 1990 | Sullivan |
4906108 | March 6, 1990 | Herrington et al. |
4913561 | April 3, 1990 | Beer |
4917506 | April 17, 1990 | Scheibner |
4917844 | April 17, 1990 | Komai et al. |
4941310 | July 17, 1990 | Kristen |
4953708 | September 4, 1990 | Beer et al. |
4973171 | November 27, 1990 | Bullard |
5006056 | April 9, 1991 | Mainstone et al. |
5040904 | August 20, 1991 | Cornwell |
5048269 | September 17, 1991 | Deni |
D320549 | October 8, 1991 | McKellar et al. |
5053091 | October 1, 1991 | Giljam et al. |
5063639 | November 12, 1991 | Boeckmann et al. |
5080155 | January 14, 1992 | Crozier |
5097956 | March 24, 1992 | Davis |
5098497 | March 24, 1992 | Brinley |
5106688 | April 21, 1992 | Bradfute et al. |
5111838 | May 12, 1992 | Langston |
5116444 | May 26, 1992 | Fox |
5121590 | June 16, 1992 | Scanlan |
5142970 | September 1, 1992 | ErkenBrack |
5203458 | April 20, 1993 | Cornwell |
5209264 | May 11, 1993 | Koyanagi |
D338399 | August 17, 1993 | Conte, Jr. |
5240112 | August 31, 1993 | Newburger |
5242516 | September 7, 1993 | Custer et al. |
5246114 | September 21, 1993 | Underwood |
5252379 | October 12, 1993 | Kuribayashi et al. |
5332095 | July 26, 1994 | Wu |
5333736 | August 2, 1994 | Kawamura |
5339959 | August 23, 1994 | Cornwell |
5352323 | October 4, 1994 | Chi |
5362351 | November 8, 1994 | Karszes |
5368394 | November 29, 1994 | Scott et al. |
5371925 | December 13, 1994 | Sawatsky |
5373965 | December 20, 1994 | Halm et al. |
5397182 | March 14, 1995 | Gaible et al. |
5402906 | April 4, 1995 | Brown et al. |
RE34929 | May 9, 1995 | Kristen |
D360578 | July 25, 1995 | Dees |
5445275 | August 29, 1995 | Curley et al. |
5450963 | September 19, 1995 | Carson |
5480030 | January 2, 1996 | Sweeney et al. |
5526843 | June 18, 1996 | Wolf et al. |
5540500 | July 30, 1996 | Tanaka |
5542902 | August 6, 1996 | Richison et al. |
5544752 | August 13, 1996 | Cox |
5549944 | August 27, 1996 | Abate |
5551213 | September 3, 1996 | Koelsch et al. |
5554423 | September 10, 1996 | Abate |
5584409 | December 17, 1996 | Chemberlen |
5592697 | January 14, 1997 | Young |
5620098 | April 15, 1997 | Boos et al. |
5638664 | June 17, 1997 | Levsen et al. |
5655273 | August 12, 1997 | Tomic et al. |
5656209 | August 12, 1997 | Benz et al. |
5665456 | September 9, 1997 | Kannankeril et al. |
5689866 | November 25, 1997 | Kasai et al. |
5699936 | December 23, 1997 | Sakamoto |
5701996 | December 30, 1997 | Goto et al. |
5709467 | January 20, 1998 | Galliano, II |
5735395 | April 7, 1998 | Lo |
5749493 | May 12, 1998 | Boone et al. |
5765608 | June 16, 1998 | Kristen |
5772034 | June 30, 1998 | Lin |
5812188 | September 22, 1998 | Adair |
5829884 | November 3, 1998 | Yeager |
5839582 | November 24, 1998 | Strong et al. |
5873217 | February 23, 1999 | Smith |
5874155 | February 23, 1999 | Gehrke et al. |
5881881 | March 16, 1999 | Carrington |
5893822 | April 13, 1999 | Deni et al. |
5898113 | April 27, 1999 | Vercere |
5908245 | June 1, 1999 | Bost et al. |
5915596 | June 29, 1999 | Credle, Jr. |
5927336 | July 27, 1999 | Tanaka et al. |
5928762 | July 27, 1999 | Aizawa et al. |
D413258 | August 31, 1999 | Voller |
5931189 | August 3, 1999 | Sweeney et al. |
5941421 | August 24, 1999 | Overman et al. |
5941643 | August 24, 1999 | Linkiewicz |
5954196 | September 21, 1999 | Lin |
5957831 | September 28, 1999 | Adair |
5971613 | October 26, 1999 | Bell |
5996800 | December 7, 1999 | Pratt |
6021624 | February 8, 2000 | Richison et al. |
6023914 | February 15, 2000 | Richison et al. |
6029810 | February 29, 2000 | Chen |
6030652 | February 29, 2000 | Hanus |
6035769 | March 14, 2000 | Nomura et al. |
6039182 | March 21, 2000 | Light |
6045006 | April 4, 2000 | Fraxier et al. |
6045264 | April 4, 2000 | Miniea |
6053606 | April 25, 2000 | Yamaguchi et al. |
D425786 | May 30, 2000 | Voller |
6059457 | May 9, 2000 | Sprehe et al. |
6070728 | June 6, 2000 | Overby et al. |
6074677 | June 13, 2000 | Croft |
6076967 | June 20, 2000 | Beaudette |
6077373 | June 20, 2000 | Fletcher et al. |
6089271 | July 18, 2000 | Tani |
6105821 | August 22, 2000 | Christine et al. |
6116781 | September 12, 2000 | Skeens |
6161716 | December 19, 2000 | Oberhofer et al. |
6164826 | December 26, 2000 | Petkovsek |
6202849 | March 20, 2001 | Graham |
6220702 | April 24, 2001 | Nakamura et al. |
6224528 | May 1, 2001 | Bell |
6227706 | May 8, 2001 | Tran |
6231234 | May 15, 2001 | Gebhardt |
6231236 | May 15, 2001 | Tilman |
6274181 | August 14, 2001 | Richison et al. |
D451542 | December 4, 2001 | Ishizawa et al. |
6357915 | March 19, 2002 | Anderson |
6402873 | June 11, 2002 | Fujii et al. |
6408872 | June 25, 2002 | Skeens et al. |
6423356 | July 23, 2002 | Richison et al. |
6520071 | February 18, 2003 | Lanza |
6799680 | October 5, 2004 | Mak |
20010023572 | September 27, 2001 | Savage et al. |
20030070751 | April 17, 2003 | Bergevin et al. |
20040000501 | January 1, 2004 | Shah et al. |
20040000502 | January 1, 2004 | Shah et al. |
20040000503 | January 1, 2004 | Shah et al. |
20040007494 | January 15, 2004 | Popeil et al. |
0723915 | July 1996 | EP |
0 836 927 | April 1998 | EP |
1053945 | November 2000 | EP |
55-090364 | July 1980 | JP |
62-192779 | August 1987 | JP |
07-299865 | November 1995 | JP |
08-009740 | April 1996 | JP |
09-131846 | May 1997 | JP |
09-252919 | September 1997 | JP |
10-034760 | February 1998 | JP |
10-138377 | May 1998 | JP |
10-180846 | July 1998 | JP |
11-34277 | February 1999 | JP |
11-077903 | March 1999 | JP |
11-115142 | April 1999 | JP |
11-254631 | September 1999 | JP |
2000-015767 | January 2000 | JP |
2000-218746 | August 2000 | JP |
UT 248033 | May 1995 | KR |
WO00/71422 | November 2000 | WO |
WO 02/28577 | April 2002 | WO |
WO02066227 | August 2002 | WO |
WO02074522 | September 2002 | WO |
WO2004/078609 | September 2004 | WO |
Type: Grant
Filed: Mar 15, 2004
Date of Patent: Apr 14, 2009
Patent Publication Number: 20040256050
Assignee: Sunbeam Products, Inc. (Boca Raton, FL)
Inventor: Hongyu Wu (San Jose, CA)
Primary Examiner: Jill L Heitbrink
Attorney: Lawrence J. Shurupoff
Application Number: 10/801,950
International Classification: B29C 47/06 (20060101);